President Barack Obama on Sunday urged respect and restraint from Americans angered by the killing of black men by police, saying anything less does a “disservice to the cause” of ridding the criminal justice system of racial bias.

He also urged law enforcement to treat seriously complaints that they are heavy-handed and intolerant, particularly toward minorities.

“I’d like all sides to listen to each other,” Obama said in response to a reporter’s question after he met with Spain’s acting prime minister, Mariano Rajoy, during an abbreviated first visit to Spain as president.

Obama’s appeal for greater understanding from opposing sides of the emotionally charged debate over police practices followed the weekend arrests of scores of people in Louisiana and Minnesota who protested the shooting deaths by police of black men in both states last week.

Those deaths were followed by a stunning sniper attack last Thursday in Dallas that killed five police officers and wounded seven others as they watched over a peaceful protest of the week’s earlier shootings.

Among those arrested in Louisiana was an activist prominent in the Black Lives Matter movement, which gained national prominence following earlier deaths of mostly unarmed black men at the hands of police across the U.S.

Obama, in his remarks, urged protesters to recognize that police officers have a difficult job.

“Whenever those of us who are concerned about failures of the criminal justice system attack police, you are doing a disservice to the cause,” Obama said, the fourth straight day that he has commented on the distressing chain of events at home.

The president’s remarks on the issue likely foreshadowed the message he will deliver Tuesday in Dallas, when he addresses an interfaith memorial service for the slain officers. He was invited to speak by Mayor Mike Rawlings, the White House said.

Obama repeated Sunday that most U.S. police officers do a good job, and said rhetoric portraying them as doing otherwise does little to build support for eliminating racial bias from the criminal justice system.

“Maintaining a truthful and serious and respectful tone is going to help mobilize American society to bring about real change,” Obama said.

The president also called for balance from law enforcement. “I would hope that police organizations are also respectful of the frustrations that people in these communities feel and not just dismiss these protests and these complaints as political correctness,” he said.

“It is in the interest of police officers that their communities trust them,” Obama said.

Some of Obama’s critics have accused him of helping create an environment for attacks on law enforcement by blaming their conduct in previous incidents and sympathizing with Black Lives Matter and other groups that complain about racial unfairness in the justice system.

The president traveled to Spain after attending a NATO summit in Poland, but the sheer horror over the killings overshadowed most of his public appearances in both countries. Spain, nevertheless, was thrilled to welcome the first U.S. president to visit in more than a decade. Tourists and curiosity seekers lined some streets in hopes of catching a glimpse of Obama, and local TV aired wall-to-wall coverage of his movements.

Obama was supposed to spend two days in Spain but cut the visit to about a day because of the shootings.

“We’ve had a difficult week in the United States,” he told King Felipe VI before they met privately at the Royal Palace.

Obama also expressed gratitude for Spain’s military contributions as a fellow NATO ally, and for hosting U.S. sailors and guided missile destroyers at a naval base on the southern coast. Obama visited the base and met with troops stationed there before the flight back to Washington.

It took the White House more than seven years to lock in Spain on Obama’s foreign travel schedule. But the shootings and the depth of the response to them forced Obama into a more hurried visit instead.

“I was hoping for a longer stay,” Obama told Rajoy. He pledged to return as an ex-president some day because Spain’s food, culture and climate are “hard to resist.”

(AP)